This invention relates to devices containing frictional pivots in general, and more particularly but not necessarily to devices such as laser levels, which rely on frictional pivots for gravitational alignment of pendulous components about an axis.
The accuracy of such a device depends upon the accuracy with which the pendulous components align with gravity. Any misalignment leads to inaccuracy in the device. Friction in the point or points about which the pendulous components pivot is the chief cause of this misalignment. Conventionally, this problem is addressed by reducing friction in the pivot by employing such means as lubrication or precision roller bearings.
Unfortunately, this conventional solution generates further problems, one of which is that as friction is reduced in the pivot, so the pendulous components take longer to stop oscillating and come to rest. As accurate readings cannot be taken until the pendulous components come to rest, the lower the friction of the bearing, the longer the user must wait before taking a reading and therefore the more inconvenient it is to use the device. The conventional solution to this problem is to apply damping means to reduce the oscillations.
A further problem with very low-friction pivots is that the pendulous components are easily disturbed by stray environmental influences, setting up further oscillations of the pendulous components, incurring further delays in readings and inconvenience to the user.
Thus it can be seen that the conventional solution to the problem of inaccuracy caused by misalignment leads to expensive and complicated solutions which generate further problems necessitating more expense and complication in their solution.